SC-CAMLR-VII

The fish diet (45% of total diet by weight) of Wandering Albatrosses rearing chicks at South Georgia during the austral winters of 1983 and 1984 was investigated using otoliths retrieved from regurgitations. These provide the first quantitative data for this species and for any albatross. By number of identified otoliths (32% could be identified only as ?Macrouridae and ?Moridae), Read More
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The terrestrial environment of Signy Island, South Orkney Islands, maritime Antarctic, is undergoing rapid and possibly irreversible change caused by a natural biological agent. During the past decade there has been a dramatic increase in the number of Antarctic fur seals Arctocephalus gazella coming ashore on the island during the short summers. It is not known whether significant numbers of Read More
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steelon codends used in commercial fishery, with a nominal mesh size A = 80 mm and A = 100 mm, made of double twines with a thickness of 4.2 mm. The studies covered 6 major fish species.
1. It appears from the study that Antarctic icefish and bumphead notothenia are subject to selection during trawling, although the effectiveness of this process - especially in the latter case - is not Read More
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As part of the NMFS/AMLR program to provide information for the effective management of Antarctica’s marine living resources, three permanent monitoring sites were established on the western side of the Antarctic Peninsula. Listed from north to south, these were Seal Island (Elephant Island), Admiralty Bay (King George Island) and Palmer Station (Anvers Island). During 1987 - 1988, preliminary Read More
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The report describes the land based ecosystem monitoring studies conducted in three separate areas of the Antarctic Peninsula marine mammal s and birds. In addition, a joint U.S./Chilean cruise to track fu r seals and penguins at sea is described.

In the vicinity of the northern tip of Antarctic Peninsula, the Bransfield Straits and South Shetland Islands, cold polar waters from the Weddell Sea meet warmer circumpolar water from the Pacific Ocean. A series of fronts form which collectively are referred to as the Weddell-Scotia Confluence. Within the Confluence region the Weddell Gyre water is separated from the Pacific or Scotia Sea Read More
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A general framework is presented to develop, test and integrate component models of the distribution and dynamics of Antarctic krill population at various spatial and temporal scales. We suggest that models of increasing complexity be developed iteratively for variability and patchiness of krill abundance. Incremental models should then be compared to statistical descriptions of the observed Read More
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The hydroacoustic survey found a low krill abundance in most areas covered by last years survey. The total biomass in the vicinity of Elephant Island was estimated from 120 kHz data to be 260 k tons and that in the Bransfield Strait South of King George Island was 39 k tons for a total of 299 k tons in the combined areas. The estimated 200 kHz survey data were higher, giving 715 k tons near Read More
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Two primary issues are at question for hydroacoustic assessments of krill, The first is the methods applied to establish biomass in a survey area and the second is the improvement in accuracy of target-strength measurements. In the case of statistical methods, there are no clear guidelines for deciding what method is most appropriate, this is made even more difficult by the fact that most Read More
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Commercial fish stocks around South Georgia have been declining since the early 1970's. A survey to monitor these stocks was carried out from December 1987 to January 1988. It complements earlier surveys in the same area and showed that most of the stocks are continuing to decline. Notothenia rossii is showing no signs of recovery and Champsocephalus gunnari is likely to continue declining in Read More
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The heavily exploited fish stocks of South Georgia have been declining since the early 1970's. Use of a non-parametric method revealed a significant change in this community from the 1986/87 survey to the 1987/88 survey. This change was the result of reductions in the abundance of Champsocephalus gunnari and Notothenia squamifrons, and the increased presence of Pseudochaenichthys georgianus. Read More
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Acoustic data obtained on the 4-5 January 1987 aboard the R/V Professor Siedlecki were used in three descriptors of krill spatial aggregation: power spectra for krill biomass fluctuations in space, semivariogram (spatial autocorrelation of krill biomass) and the frequency distribution of krill biomass estimate. The wavenumber spectrum resembles a white noise at scales of 2-20 km, although at Read More
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The vertical trajectory of phytoplankton in the Antarctic ocean is modelled as a random walk with a diffusivity derived from a simple Ekman layer model and turbulence theory. The surface mixing layer is shallow, but diffusion is large enough to effect the vertical distribution of phytoplankton in the upper ocean.

Encaged aggregations of swimming krill have been measured at 38 and 120 kHz. The results indicate that the target strength values are substantially lower than previously assumed.

At-sea metabolism (C02 production) and water turnover of six breeding Grey-headed Albatrosses Diomedea chrysostoma were measured, using the doubly labelled water method, at Bird Island, South Georgia. Mean food consumption (estimated from a water influx rate of 1.01 l d-1 and data on dietary composition) was 1200 g d-1 or 50.4 W. At-sea metabolism (derived from a rate of CO2 production of 3.98 Read More
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Many data on the diets of important vertebrate predator species in Prydz Bay and around the sub-Antarctic Heard and Macquarie Islands have been collected during the last seven years. Published and unpublished results are collated and summarised, and several important points emerge.
In Prydz Bay, on which is centered the CCAMLR Ecosystem Monitoring Programme's priority study area, Euphausia Read More
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This paper includes information on the trend of the elephant seal population at Stranger Point (25 de Mayo-King george I.) between 1980-87(excluding 1981). A decline in the population was observed in 1980-82 and 1987. The female component was mainly affected in 1 980-82 (r=-0.568) while the male component was affected in 1987 (r=-0.463). A possible influence of El Niño Southern Oscillation ( Read More
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A model is set up for the operation (which includes both searching and fishing) of a Japanese krill trawler over a half-month period. It is based on an underlying krill distribution model whose parameters are determined primarily from the scientific FIBEX surveys. Output from the model of the operation is compared with (and partially tuned to) statistics for a sample of data from the Read More
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Current knowledge of the ecology, biology and life history of the Antarctic krill Euphausia superba Dana is reviewed. Emphasis is placed on recent developments, particularly on the results of various national and international research programmes loosely co-ordinated under the auspices of BIOMASS (Biological Investigations of Marine Antarctic Systems and Stocks). Attention is focused on topics Read More
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Hydroacoustic surveys of the distribution and abundance of krill, Euphausia superba Dana, were undertaken in the Prydz Bay region, Antarctica. Three surveys were carried out south of 60°S within an area of 1.28 x l06 km2 between 55°E and 95°E, during the austral summer months of 1980-81, 1983-84 and 1984-85. The surveys included a total of 25 transects and covered a distance of 22 500 km over Read More
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Mesh selectivity experiments for several finfish species were conducted during the Spanish antarctic cruise “ANTARTIDA 8611” using the covered codend technique.
This paper presents the results obtained for Notothenia gibberifrons and Champsocephalus gunnari.
Selection factors calculated following different methods with a codend mesh of 68 mm were 2.87 for Notothenia gibberifrons and 3. Read More
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Biological characteristic and distribution of the green Notothenia by depth are given based on the results of inventory trawling surveys carried out in 1984/1985 and 1986/1987 by the BMRT "Gizhiga" in the Antarctic Peninsula subarea. Also presented are the abundance and biomass indices and the estimate of this species biomass by location and for the subarea on the whole. According to the Read More
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